Hose pump



J. ZIMMER HOSE PUMP Dec. 24, 1968 Filed June 6, 1967 3Sheets-Sheet 1Prior Art Dec. 24, 1968 J. ZIMMER 3,417,707

HOSE PUMP Filed June 6, 1967 3 Sheets-Sheet 2 J. ZIMMER Dec. 24, 1968HOSE PUMP Filed June 6. 1967 3 Sheets-Sheet 3 Fig-17 United StatesPatent 3,417,707 HOSE PUMP Joseph Zimmer, 2 Rue du Canal,Illkirch-Gratfenstaden, France Filed June 6, 1967, Ser. No. 643,877Claims priority, application France, June 15, 1966,

,sss 17 Claims. (Cl. 103-148) ABSTRACT OF THE DISCLOSURE A hose pumpcomprising a flexible hose having an inlet end and an outlet end and apair of branches between the ends, the branches of the hose extendingbetween a pair of fixed rigid abutment plates and a pair of movableplates are arranged spaced in longitudinal direction of the hose in thespace between the branches. Upstream and downstream extremities of theplates are alternatingly moved to and fro in a predetermined sequence ina direction substantially normal to said abutment plates between a pairof end positions in which they press the engaged branch portionsfluid-tightly against the respective abutment plates to thereby pumpfluid from the inlet to the outlet end of the hose.

Background of the invention The present invention relates to pumps forpumping fluid, preferably liquid, and more specifically, the presentinvention relates to a hose pump.

Hose pumps are known in the art which comprise at least one andpreferably a plurality of substantially parallel hoses formed fromflexible and elastic material. In order to pump the fluid, the hoses areat longitudinally spaced portions thereof tightly compressed by rollersor the like arranged spaced at a given distance from each other andmoved in direction in which the fluid has to be pumped. Each of therollers is moved in the aforemen tioned direction from a startingposition to an end position and in reaching the end position it isdisengaged from the hose and moved back again to the starting position.The fluid in the hose is thereby pumped in the desired direction.

This pump known in the art, has however the disadvantage that the flowof the fluid produced by the pump is irregular and under certainconditions intermittent. Such intermittent or uneven flow of fluid ishighly undesirable in many applications, and while this known hose pumpis of simple construction, the above mentioned disadvantages of the pumplimit its field of application.

It is an object of the present invention to provide for a hose pumpwhich overcomes the disadvantages of the hose pump known in the priorart mentioned above.

It is an additional object of the present invention to provide for ahose pump which during operation will produce a continuous flow of fluidin one direction.

Summary of the invention With these objects in view, the hose pumpaccording to the present invention mainly comprises at least oneflexible hose having an inlet and an outlet end, and a pair of branchesbetween the ends, the branches communicate with each other at the inletand the outlet end and define between themselves an elongated space, apair of fixed rigid abutment plates extending spaced from each other inlongitudinal direction of the hose and the branches of the hoseextending between the pair of abutment plates, a pair of movable platesextending in longitudinal direction of the hose and arranged spaced fromeach other in the aforementioned direction in the elongated spacebetween the branches, and operating means 3,417,707 Patented Dec. 24,1968 connected to the plates in the region of their upstream anddownstream extremities for moving the upstream and downstreamextremities to and fro in a direction transverse to the longitudinaldirection of the hose and in a predetermined sequence such that thecorresponding extremities of the pair of plates are always moved simultaneously between a first end position adjacent one of the pairs of thepair of abutment plates and a second end position adjacent the other ofthe pair of abutment plates, while the other extremity of each plateremains at rest in one of the end positions during this movement andeach 'of the extremities in the end positions thereof fluid-tightlyclamps the engaged branch against the abutment plate adjacent therespective extremity, whereby fluid is pumped from the inlet to theoutlet end of the hose.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

Brief description of the drawing FIG. 1 is a schematic cross-sectionalview of a hose pump according to the prior art;

FIGS. 25 are longitudinal cross-sections taken along the axis of thehose and illustrating the hose pump according to the present inventionin four successive positions;

FIG. 6 is a schematic figure illustrating the conditions to determine apreferred distance between the abutment plates;

FIG. 7 is a diagram illustrating a preferred movement of the oppositeextremities of each movable plate;

FIG. 8 is a side View of a control cam forming part of the operatingmeans for moving the movable plates;

FIG. 9 is a longitudinal cross-section of an improved pump according tothe present invention;

FIG. 10 is a longitudinal cross-section through a modification of a pumpaccording to the present invention constructed to produce a fluid flowin which the pressure of the fluid pumped varies in a predeterminedsequence;

FIGS. ll-l4 are schematic views illustrating the operation of the pumpillustrated in FIG. 10;

FIG. 15 is a diagram illustrating the pressure in the fluid pumped bythe pump according to FIG. 10 as a function of time;

FIG. 16 is a sectioned view and showing the operating means of the pumpaccording to the present invention in detail, the section being takenalong the line XVI-XVI of FIG. 17; and

FIG. 17 is a top view of the pump arrangement shown in FIG. 16 with someparts broken away to show the parts beneath the same.

Description of the preferred embodiments Before describing theembodiments of the pump according to the present invention, reference ishad to FIG. 1 of the drawings in which a hose pump according to theprior art is schematically illustrated. As schematically shown in FIG. 1the hose pump according to the prior art comprises at least one hose 1of flexible elastic material which abuts at one side thereof with aportion of its length against a plane surface of a fixed support orabutment means 2. The hose 1 is further engaged at the opposite sidethereof by a pair of rollers 3 and 3' or the like arranged spaced inlongitudinal direction from each other and moved for instance by a pairof endless chains, not shown in the drawing, in the direction of thearrows a. The rollers 3 and 3' are pressed either solely by theirweight, or by additional means not shown in the drawing, against thehose 1 respectively against the support 2 in such a manner tofluidtightly close the engaged hose portion. Due to its elasticity thesubstantially circular hose will, after the respective roller has passedover a portion thereof, again snap back to its original circularposition so that during movement of the rollers in the direction of thearrows a the fluid coming in the illustrated example from the left, asshown in FIG. 1, will be sucked inwardly to the left of the roller 3.The fluid enclosed in the portion 1 of the hose 1 between the rollers 3and 3 is thus transported in the direction indicated by the arrows a.When the respective roller arrives at the right edge of the plate 2, asviewed in FIG. 1, the roller is lifted in order to be returned by theendless chains not shown in the drawing to the other side of the plate2, that is the left side, as viewed in FIG. 1. The fluid ahead of theroller 3 is pushed in the direction indicated by the arrow a. Thepressure P of the fluid enclosed in the portion 1' of the hose 1 betweenthe rollers 3 and 3' is selectively equal to the pressure F on thesuction side, whereas the pressure P of the fluid pushed in thedirection of the arrow a is superior to this pressure, sometimes evenconsiderably superior depending on the apparatus to which the fluid istransported. Therefore, at the moment at which the roller 3 leaves thehose 1 in order to return to its starting position, the pressure Pprevailing over the pressure P will provoke a return shock so that theflow of the fluid will become irregular. Under certain conditions, thefluid flow may stop completely or even reverse itself during a shortinstant while causing a slight swelling of the portion 1' of the hose 1.

The above described apparatus according to the prior art has therefore,as mentioned above, the disadvantage to provide an irregular fluid flow.

Referring now to FIGS. 2-5 in which the acting elements of oneembodiment of a hose pump according to the present invention areillustrated in successive positions, it will be seen that the hose pumpillustrated in these figures mainly comprise at least one flexible hosehaving an upstream inlet end portion 11 and a downstream outlet endportion 11" and a pair of branches 11a and 1111 between theaforementioned end portions which communicate with each other at theinlet and outlet end portion while defining between themselves anelongated space. The branches 11a and 11b of the hose extend between apair of fixed rigid abutment means or abutment plates 12a and 12bextending spaced from and substantially parallel to each other so thatthe facing surfaces thereof are in contact with outer portions of thebranches 11a and 11b. While FIGS. 2-5 illustrate only a single hose, thepump according to the present invention preferably comprises a pluralityof hoses having each a pair of branches 11a and 1112, which hoses extendparallel to and transversely spaced from each other as for instanceclearly shown in FIG. 17, and the plurality of hoses may be connected toeach other at the upstream and downstream side. It is mentioned that theterm upstream and downstream are used in the specification only toindicate the direction of fluid flow that is the term upstreamdesignates the side at which the fluid is sucked in, whereas the termdownstream designates the side at which the fluid is transported. Theterms are not used to indicate a level or pressure difference, and thepressure or the level of the fluid at the downstream side may be greateror higher than on the upstream side.

Each hose 11 is formed from flexible and elastic material so that thehose after being compressed in transverse direction, and after thepressure is relieved will resiliently snap back to its originalconfiguration or cross-section, which may for instance be circular.

Two movable striker elements preferably in the form of plates 14 and arearranged spaced from each other in direction of the elongation of thehose in the elongated space between the two branches 11a and 11b. Rods16, 17, 13 and 19 respectively extend through the plates 14 and 15 inthe region of the extremities thereof substantially normal to theelongation of the hose, and each of the rods has a pair of opposite endportions projecting beyond the respective plate so as to be engageableby operating means, which will be described later on in detail, servingto move the plates in a predetermined sequence.

FIG. 2 illustrates the pump in a position in which the plate 14 at theupstream side is pressed over its whole length against the hose branch11b, respectively against the abutment plate 1212 so that the branch 11bis complete and fluid-tightly compressed over the whole length of theplate 14. At the same time, the plate 15 on the downstream sidecompresses the branch 11a against the abutment plate 12a. From theposition as shown in FIG. 2, the rod 16 arranged at the upstream side ofthe plate 14 is moved by the operating means of the pump in thedirection indicated by the arrow b, whereas simultaneously the rod 18arranged at the upstream side of the plate 15 is moved in the directionindicated by the arrow c. During this movement the downstreamextremities of the two plates are maintained in abutment against thebranches of the hose to compress the same respectively at 31 and 32 soas to interrupt fluid flow at these locations. Due to this movement ofthe plates which brings the same to the position as indicated in FIG. 3,the fluid located in the portion 21 of the branch 11a is in partdisplaced, in the direction as indicated by the arrow k, towards theportion 24 of the branch 11a, which portion increases as the portion 21decreases. At the same time, the fluid in the portion 22 of the branch11b is moved in part in the direction indicated by the arrow 1 andpushed out through the downstream end portion 11 in the directionindicated by the arrow a, while at the upstream side the fluid is suckedinto the portion 23 of the branch 11b, in the direction of the arrow inas the portion 23 increases during displacement of the plate 14.

After the plates 14 and 15 have taken up the positions as shown in FIG.3, the rods 16 and 18 are maintained in position so as to respectivelypress the extremities of the plates through which they extend tightlyagainst the branches 11a and 11b to compress these branches at thelocations 33 and 34 during the following part of the cycle of movementof the plates in which the rod 17 at the downstream side of the plate 14is moved in the direction indicated by the arrow d, and the rod 19arranged at the downstream side of the plate 15 is simultaneously movedin the direction indicated by the arrow e until the plates 14 and 15arrive at the position illustrated in FIG. 4. Due to this movement, theremainder of the fluid in the portion 22 of the branch 11b is moved inthe direction indicated by the arrows 1 toward the downstream outlet endportion 11', whereas the remainder of the fluid from the portion 21 ofthe branch 11a is pushed in the direction of the arrow m through theintermediate portion 25 into the portion 24 of this branch. The portion23 of the branch 11b continuously increases and it is filled with suckedin fluid from the upstream side flowing in the direction of the arrow m.

During the following part of the cycle of operation of the pump the rod16 of the plate 14 is moved in the direction of the arrow 1 and the rod18 of the plate 15 is moved in the direction of the arrow g, whereas thedownstream extremities of the plates remain pressed against the branches11a and 11b to compress the same in fluid-tight manner respectively atthe locations 35 and 36. The plates thus moved will reach the positionas indicated in FIG. 5. A certain amount of fluid which is located inthe portion 24 of the branch 11a is pushed in the direction of arrow ptoward the downstream outlet end 11', whereas fluid is sucked in at theupstream end in the direction of the arrow k into the increasing portion21 of the same branch. The fluid in the portion 23 of the branch 11b isdisplaced in part in the direction of the arrow q through theintermediary portion 26 into the non tion 22 of the same bnanch, whichlast mentioned portion increases as the plate 15 is displaced.

After the plates have reached the position as illustrated in FIGURE 5,the downstream extremity of the plate 14 is displaced by means of therod 17 and in the direction of the arrow h whereas the correspondingextremity of the plate 15 is displaced by means of the rod 19 at thesame time in the direction of the arrow i. During this movement theupstream extremities of the plates compress the branches 11a and 11btightly and respectively at the locations 37 and 38.

The rest of the fluid located in the portion 24 of the branch 11a isthereby pushed in the direction of the arrows p towards the downstreamend portion 11 to be further transported in the direction of the arrowa. The fluid contained in the portion 23 of the branch 11b passesthrough the intermediary portion 26 in the direction of the arrow q intothe portion 22. Finally, the portion 21 of the branch 11a whichincreases as the plate 14 is displaced remains fluid-tightly compressedat 38 and continues to suck fluid from the upstream side. At the end ofthis phase of operation, the plates are again in the position asillustrated in FIG. 2 and the four steps of the cycle above describedare repeated.

While not absolutely necessary, it is advantageous to choose thedistance between the facing surfaces of the abutment plates 12a, 12b ina manner as will be explained with reference to FIG. 6. In FIG. 6, theinner diameter of each branch 11a and 11b of the hose is designated withD, the wall thickness of the branches is designated with E, whereas Bdesignates the thickness of the plates 14 and 15, of which only theupstream end portion of the plate 14 is shown in FIG. 6. The distance Ais preferably chosen to correspond exactly or at least approximately tobut of course, it is also possible to choose the distance A in specialcases smaller or larger. When the distance between the abutment platesis chosen as indicated in the above formula, the pump can be easilyadapted for different outputs, whereby only the hoses with their twobranches have to be exchanged against hoses having branches of an innerdiameter according to the desired output and the dimensions andproperties of which will correspond to the above formula.

A certain problem arises due to the alternating displacement of the twoextremities of the plates in direction transverse to the elongation ofthe plates. In principle the extremities of the plates will always pivotalternatingly about the axis of the rod maintained at rest during therespective phase of operation and the extremities of the plates willfollow a circular course, so that the plates will have the tendency tobe displaced toward the downstream side of the pump as indicated by thedotted lines in FIG. 7 in which the rod 16 follows a path KLM, whereasthe rod 17 follows a course N-P-Q. In order to overcome thisdisadvantage, the rods 16 and 17, 18 and 19 may be guided in the manneras schematically illustrated in FIG. 7 for the rods 16 and 17. Duringthe first part of the abovedescribed cycle the plate 14 turns about theaxis of the rod 17 which is maintained in place and the rod 17 willfollow a circular path indicated by the arrow 1; and move from K to L.During the second part of the cycle the rod 17 which is displaced in thedirection indicated by the arrow e is guided along a straight lineperpendicular to the facing surfaces of the abutment plates 12a and 1211so as to move from the point N to the point P. During this movement, therod 16 has to be displaced, in the direction parallel to the plate 12aas indicated by the arrow x so as to move from L to L. The distancebetween the axes of the rods 16 and 17 is designated with G and thedistance between the points L and L corresponding to the movement of therods 16 parallel to the plane of the abutment plates is designated withF. The movements during the third and fourth part of the above describedcycle will take place in the same manner but in the opposite direction,that is the rods 16 will describe a circular path While turning aboutthe point P and it is then displaced parallel to the abutment plateuntil it reaches the point of its departure K, while the rod 17 isguided along the same straight line from the point P to the point N.

Various constructions are possible which will permit movement of therods 16 and 17 in the manner as described above, and one of the variouspossible constructions will be described later on in further detail. Therods 18 and 19 of the plate 15 are guided in the same manner. Of course,it is to be understood that instead of guiding the rods at thedownstream end of each plate, along a substantially straight path it isalso possible to guide the rod at the upstream end of each plate along astraight path, whereas the rod at the downstream end of each plate willin this case describe a circular movement and be then displaced indirection parallel to the abutment plate.

In FIGS. 25 the pressure of the fluid at the upstream side is designatedwith P and the pressure at the downstream side is designated with P; thepressure of the fluid which is enclosed in the positions of the platesshown in FIGS. 35 between the point of compression 32 and 33 that is inthe portions 21, 24 and 25 of the branch 11a, or between the points ofcompressions 36 and 37, that is in the portions 22, 23 and 26 of thebranch 11b is designated with P. During the first part of the abovedescribed cycle in which the plates move from the position indicated inFIG. 2 to the position indicated in FIG. 3, the portion 21 of the branch11a communicates with the upstream end 11 of the hose in which thepressure P is maintained, whereas the portion 22 of the branch 11bcommunicates with the downstream end 11 in which the pressure P ismaintained, which pressure P is superior to the pressure P When theposition according to FIG. 3 is reached the pressure P will be equal tothe pressure P At this moment the plate 15 will start its movementindicated by the arrow e establishing thereby, at the location 32,communication between the portion 24 of the branch lit: with thedownstream end 11. Since the pressure P is inferior to the pressure P,there could be produced a momentary variation of the pressure P whichwould provoke an irregularity in the flow. To avoid such anirregularity, it is possible to give, at the start of the second part ofthe cycle, to the rod 17 a pronounced acceleration in the direction ofthe arrow d while retarding the movement of the rod 19 and in order toproduce this effect it is for instance possible to form cams whichcontrol the movement of the aforementioned rods with an appropriate camface. In this way the pressure P will rise rapidly, whereas slow openingof the passage at the location 32 will prevent a brisk return shock.During the third and fourth part of the above mentioned cycle the samemeasures may be adapted in the inverse sense.

FIG. 8 illustrates, by way of an example a control cam which may be usedfor moving the rods. The shaft 101 of the control cam turns in thedirection indicated by the arrow y. The four phases of the abovedescribed cycle are designed with I, II, III, IV. It is assumed that thecam illustrated in FIG. 8 will control the movement of the rod 17. Thecam 102 will maintain the rod 17 in place during the first part of thecycle by its small diameter portion, and the cam will produce at thestart of the second part of the cycle a pronounced acceleration of therod movement due to the rapid rise of its cam face portion 103.Subsequently it will maintain the rod in place during the third part ofthe cycle by its large diameter portion of constant radius, to finallyimpart to the rod an acceleration pronounced in the inversed directionat the start of the fourth part of the cycle due to the rapid decline ofthe flank portion 104. For the rod 19 opposite movements are obtained byreversing the portions of the cam.

When the difference between the upstream and the downstream pressure isconsiderable it is possible that the above described means will not besufficient to avoid an irregularity of the fluid flow. This disadvantagemay be overcome according to a further characteristic of the inventionby providing two movable plates of different length and by arranging thelonger plate at the upstream end of the pump, while using cam discs asdescribed above in order to obtain increased, respectively reducedaccelerations for the rods 17 and 19.

FIG. 9 illustrates such a pump in which the plates are shown inpositions they will attain during the second part of the above describedcycle. The length L of the plate 14' is superior to the length L of theplate 15 so that the volume of the portion 21 of the branch 11a issuperior to that of the portion 23. It is evident that in this way arapid rise of the pressure P at the beginning of the second part of thecycle may be obtained, especially when using the special cam form abovedescribed, since a quantity of fluid corresponding to the volume of theportion 21 of the branch 11a is pushed toward the portion 23 of smallervolume.

Based on the above described principle it is also possible to constructa pump which produces a fluid flow which is not constant but in whichthe pressure and the flow will vary in a predetermined manner as afunction of the time, without however risking a stoppage of the fluid ora momentary flow in the opposite direction. In order to obtain thiseffect the pump may be provided, according to another feature accordingto the present invention, with two movable plates having greatlydifferent length and in which the longer plate is arranged upstream.

FIG. illustrates a pump of this type. The length L of the upstream plate14" is considerably greater than the length L' of the downstream plateso that the volume of the portion 41 of the branch 11a is much greaterthan that of the portion 42 of the branch 11b. FIGS. 11-14 illustrate ina very schematic manner the function of this pump. The pump illustratedin FIG. 10 will operate in a four phase cycle corresponding to the cycledescribed in connection with FIGS. 2-5, with the sole difference thatthe volumes of the portions 41 and 43 of the two branches are greatlysuperior to the volumes 44 and 42 of the same branches, so that thespeed of the fluid expelled during the scond part of the cycle (volume41) and during the fourth part of the cycle (volume 43) rises rapidly,as compared with the speed obtained during the first part (volume 42)and the third part (volume 44) of the cycle.

The pressure P at the downstream side will thereby vary according to thediagram of FIG. 15, showing the peaks Pa which follow each other in asequence resulting from the operation of the pump, without however,dropping below a certain minimum value Pb. Such a pump is adapted toimitate exactly the beat of a heart, provided the pump is operated in anappropriate time sequence. On the other hand, the pump according to thepresent invention permits to obtain a fluid flow of absolute constantspeed and pressure. The pump according to the present invention may beused therefore for various applications especially in scientificlaboratories, for example for carrying out rheological measurements oras aid during surgery. While the pump according to the present inventionis preferably used for pumping liquids it can, evidently, also serve forpumping or compressing gases.

FIGS. 16 and 17 more completely illustrate a pump according to thepresent invention, and these figures especially illstrate the operatingmeans for moving the plates 14 and 15 of the pump in the above describedmanner. As shown in FIG. 17 the pump may comprise a plurality of hoses11 arranged parallel and spaced from each other at a certain distance topermit compression of the branch portions 11a and 11b of each hose inthe above described manner. The branches 11a and 11b of all hoses arelocated between the abutment plates 12a and 1212 which are supported ona frame schematically illustrated in FIGS. 16 and 17 and which includesa base plate 90 and an intermediate plate located between the base plateand the abutment plate 12b. A drive motor 111 is mounted on an extensionof the base plate and the drive shaft 112 of the motor 111 is preferablycoupled by a flexible coupling 113 to a coaxial shaft portion 114supported on appropriate bearing blocks on the base plate 90. A pinion115 keyed to the shaft portion 114 meshes at opposite sides thereof withgears 116a and 1161) respectively keyed to a pair of parallel shafts117a and 117]) turnably mounted on appropriate bearing blocks on thebase plate. Each of the shafts 117a and 1171] carries four cams 160,170, and arranged on the respective shaft spaced from each other as bestshown in FIG. 16, and respectively cooperating with the rods 16, 17, 18and 19 of the plates 14 and 15. The aforementioned cams preferably havea configuration as shown in FIG. 8. Rollers or cam followers 169, 179,189 and 199 respectively engage the peripheral surfaces of the cams 160,170, 180 and 190 and the aforementioned rollers are turnably carriedrespectively in the lower forked ends of guide rods 161, 171, 181 and191 which are respectively guided for reciprocating motion in thedirection of the arrows A in guide bushings provided in the abutmentplates 12a, 12b and in the intermediate plate 85. Each of the rods isprovided intermediate the abutment plate 12b and the intermediate plate85 with a fixed collar and compression coil springs 167, 177, 187 and197 are respectively wound about the aforementioned rods abutting withtheir lower ends on the respective collar and at the upper ends againstthe bottom surface of the plate 12b, to thereby press the rollersrespectively carried by the rods against the corresponding cam surfaces.

The pairs of guide rods 161, 171, 181 and 191 are respectively connectedto opposite ends of the rods 16, 17, 18 and 19 to move the latter asdescribed in connection with FIG. 7. For this purpose, the opposite endsof the transverse rod 17 are respectively pivotally connected at 173 tothe guide rods 171, whereas the opposite ends of the transverse rod 19are respectively pivotally connected at 193 to the guide rods 191. Theguide rods 161 and 181, on the other hand, carry, respectively,intermediate the abutment plates 12a and 12b, plates 163 and 183respectively provided with elongated transverse slots 163' and 183' inwhich the opposite ends of the transverse rods 16 and 18 arerespectively guided so that while the rods 161 and 181 are reciprocatedin the direction as indicated by the arrows A, the transverse rods 16and 18, while following the movement of the guide rods 161 and 181 maymove also in direction transverse to the elongation of the rods due tothe guiding of the end portions of the rods 16 and 18 in the transverseslots 163' and 183. The plurality of hoses and the branches thereof areheld in place by appropriate end plates 71, 72 fixed in any convenientmanner to the right ends, as viewed in FIG. 16 of the abutment plates12a and 12b and corresponding end plates 73, 74 fixed to the left endsof the plates.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofhose pumps differing from the types described above.

While the invention has been illustrated and described as embodied in ahose pump for providing a continuous flow of fluid, it is not intendedto be limited to the details shown, since various modifications andstructural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgeeadily adapt it for various applications without omitting features that,from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

I claim:

1. A hose pump comprising, in combination, at least one flexible hosehaving an inlet end and an outlet end and a pair of branches betweensaid inlet and said outlet end, said branches communicating with eachother at said inlet and said outlet end and defining between themselvesan elongated space; a pair of fixed rigid abutment means extendingspaced from each other in longitudinal direction of said hose, and saidbranches of said hose extending between said pair of abutment means; apair of movable striker elements extending in longitudinal direction ofsaid hose and being arranged spaced from each other in said direction insaid elongated space between said branches; and operating meansconnected to said striker elements in the region of the upstream anddownstream extremities for alternatingly moving the upstream anddownstream extremities to and fro in a direction transverse to thelongitudinal direction of said hose and in a predetermined sequence suchthat corresponding extremities of said pair of striker elements arealways moved simultaneously, but in opposite directions, between a firstend position adjacent one of said pair of abutment means and a secondend position adjacent the other of said pair of adjustment means whilethe other extremities of said striker elements during this movementremain at rest in one of said end positions and each of said extremitiesin said end position fluid-tightly clamping the engaged branch againstthe abutment means adjacent thereto.

2. A hose pump as defined in claim 1, wherein said abutment means areconstituted by a pair of rigid substantially parallel abutment plates,and wherein said movable striker elements are constituted by movableplates.

3. A hose pump as defined in claim 2, wherein the distance between thefacing surfaces of said abutment plates is equal to the sum of thethickness of a movable plate, plus the inner diameter of one of saidbranches, plus four times the wall thickness of a hose branch.

4. A hose pump as defined in claim 2, wherein said movable plates haveequal length.

5. A hose pump as defined in claim 2, wherein one of said movable platesis longer than the other of said movable plates.

6. A hose pump as defined in claim 5, wherein said longer movable plateis arranged upstream of the other movable plate.

7. A hose pump as defined in claim 2, and including a rod for eachextremity of each movable plate, each rod extending substantially normalto the elongation of the respective plate through the respectiveextremity and projecting with opposite end portions thereof laterallybeyond the movable plate, said operating means engaging said endportions of each rod.

8. A hose pump as defined in claim 7, wherein said operating meansinclude first guide means cooperating with one rod of each movable platefor guiding the respective extremity during its to and from movementalong a rectilinear path substantially normal to said abutment plates,and second guide means cooperating with the other rod of each movableplate and permitting said other rod to move substantially parallel tosaid abutment plates.

9. A hose pump as defined in claim 7, wherein said operating meanscomprise a plurality of cams, one for each end portion of each rod, andeach having a cam face, a single drive motor connected to said cams forrotating the same about their axes, and a plurality of transmissionmeans respectively engaging the cam faces of said cams and beingconnected to said end portions of said rods.

10. A hose pump as defined in claim 9, wherein each of said transmissionmeans comprises a guide rod, a cam follower carried at one end of eachguide rod and engaging the cam face to the respective cam, spring meansconnected to each guide rod and pressing the cam follower carriedthereby against the respective cam face and means guiding each of saidguide rods for rectilinear movement in a direction substantially normalto said abutment plates.

11. A hose pump as defined in claim 10, and including connecting meansconnecting the opposite end portions of one rod of each plate to therespective guide rods for pivotal movement about the axis of said onerod and for movement with the respective guide rods in longitudinaldirection of the latter and second connecting means connecting theopposite end portions of the other rod in each plate to the respectiveguide rods for movement with the latter in longitudinal direction andfor movement in direction transverse to said longitudinal direction.

12. A hose pump as defined in claim 1, wherein said Operating means areconstructed and arranged to displace the downstream extremities of saidstriker elements with a speed varying as a function of theirdisplacements.

13. A hose pump as defined in claim 1, wherein said operating means areconstructed and arranged to displace the downstream extremities of oneof the striker elements very fast at the beginning of its movement andto move it very slowly at the end of its movement.

14. A hose pump as defined in claim 1, wherein said operating means areconstructed and arranged to displace the downstream extremity of one ofthe plates very slowly at the beginning of its movement and very fast atthe end of its movement.

15. A hose pump as defined in claim 1, wherein said pump comprises aplurality of said flexible hoses extending spaced from and substantiallyparallel to each other between said pair of abutment means, and saidpair of movable striker elements extending through the elongated spacebetween the branches of said plurality of hoses.

16. A hose pump as defined in claim 1, wherein said branches and saidinlet and outlet ends of the hose have substantially the same innerdiameter.

17. A hose pump as defined in claim 1, wherein said hose is made fromflexible and elastic material.

References Cited UNITED STATES PATENTS 1,922,196 8/1933 Butler 103-1482,285,974 6/1942 Huber 103l48 2,769,397 11/1956 Bolger 103-148 2,961,96511/1960 Senning et a1. 103--148 3,020,846 2/1962 Thomas 103-148 FRED C.MATTERN, JR., Primary Examiner.

WILBUR I. GOODLIN, Assistant Examiner.

